1. Field of the Invention
This invention relates generally to transducer suspension systems and more particularly to a suspension system having a low profile.
2. Description of the Prior Art
Direct access storage devices (DASD), or disk drives, store information on concentric tracks of a rotatable magnetic recording disk. A magnetic head or transducer element is moved from track to track to record and read the desired information. Typically, the magnetic head is positioned on an air bearing slider which flies above the surface of the disk as the disk rotates. In some recently proposed disk drives, the slider (or carrier) rides on a liquid film or bearing on the disk. A suspension assembly connects the slider to a rotary or linear actuator. The suspension provides support for the slider.
The suspension must meet several requirements. The suspension must be flexible and provide a bias force in the vertical direction. This is necessary to provide a compensating force to the lifting force of the air bearing in order to keep the slider at the correct height above the disk. Also, the vertical flexibility is needed to allow the slider to be loaded and unloaded away from the disk. Another requirement of the suspension is that it must provide a pivotal connection for the slider. Irregularities in manufacture and operation may result in misalignment of the slider. The slider is able to compensate for these problems by pitching and/or rolling slightly to maintain the air bearing. Another requirement of the suspension is that it must be rigid in the lateral direction. This is needed to prevent the head from moving side to side, which would result in the head reading the wrong track.
Examples of suspension systems are shown in the following references: U.S. Pat. No. 4,167,765, issued Sep. 11, 1979 to Watrous; U.S. Pat. No. 4,797,763, issued Jan. 10, 1989 to Levy et al; U.S. Pat. No. 5,187,625, issued Feb. 16, 1993 to Blaeser et al; U.S. Pat. No. 5,208,712, issued May 4, 1993 to Hatch et al; European Patent Application 0487914 published Oct. 29, 1991 by Foote, et al; Japanese Patent Application 59-207065, published Nov. 24, 1984 by Hashimoto; and Japanese Patent Application 04-321918, published Nov. 11, 1992 by Yamazaki.
Disk drives have become smaller in size while at the same time the data storage capacity has greatly increased. Large capacity disk drives typically have multiple disks mounted on the same rotatable spindle. In order to accommodate more disks in the same height, the space between each disk must be greatly decreased. Also, disk drives having only a single disk may have limited space to accommodate a suspension between the disk and an outer housing. The height of the suspension has proven to be a limiting factor in realizing closer disk spacing and smaller disk drives. What is needed is a suspension system which has a very low profile, meets the performance requirements, and is inexpensive to manufacture.